John H. Kurata

Helicobacter pylori Infection and Gastric Cancer A Nested Case± Control Study in a Rural Area of Japan

We conducted a seroepidemiological nested case-control study to determine the association of gastriccancer with Helicobacter pylori infection and atrophicgastritis. A cohort of 2858 participants in an annual multiphasic health check-up werefollowed for eight years. Data for 45 gastric cancercases and 225 sex-, age-, and address-matched controlsubjects were analyzed. Helicobacter pylori infectionwas determined by IgG antibodies, and atrophicgastritis was diagnosed by both serum pepsinogen I level(≤70 ng/ml) and the pepsinogen I/II ratio (≤3.0).Univariate analysis showed that Helicobacter pylori and atrophic gastritis were significantlyassociated with gastric cancer. In a multivariateanalysis, atrophic gastritis was associated withsignificantly increased risk of cancer (odds ratio,3.38; 95% confidence interval, 1.54-7.42); however,Helicobacter pylori was not associated with cancer (oddsratio, 1.84; 95% confidence interval, 0.59-5.72). Theseresults suggest that Helicobacter pylori infection alone is not directly associated with gastriccarcinogenesis but has an indirect relation to gastriccancer through the development of atrophicgastritis.

Ulcer Epidemiology: An Overview and Proposed Research Framework

A proposed framework for integrated research in ulcer epidemiology is presented. This framework entails the integration of ulcer epidemiology information from national data sets and regional or specialized data sources to produce an organized sequence of studies. National data sets are used to determine the descriptive characteristics of ulcer epidemiology in terms of person, place, and time. Once subpopulations with high or low rates of ulcer disease are identified, hypotheses are generated to explain subpopulation differences. These etiologic hypotheses are then tested in regional or specialized study populations such as the Adventist Health Study, the Rand Health Insurance Study, or the American Rheumatism Association Medical Information System.

The incidence of duodenal and gastric ulcers in a large health maintenance organization

We report the incidence of peptic ulcers (duodenal, pyloric canal, gastric, and combined) verified by radiologic, endoscopic, or surgical evidence in a large Health Maintenance Organization (HMO) in Los Angeles, California. For members age 15 and above, the peptic ulcer incidence rate was 0.86 per 1,000 person-years (p-y) (males 1.10, females 0.63). The male to female sex ratio was 1.7. Two hundred twenty-two duodenal, 17 pyloric canal, 89 gastric, and 21 combined first-time diagnosed ulcer cases were located. For duodenal and pyloric canal ulcer, the incidence rate for members age 15 and above was 0.58 per 1,000 p-y (males 0.76, females 0.40). For gastric ulcer, the incidence rate for members age 15 and above was 0.21 per 1,000 p-y (males 0.23, females 0.18). The combined ulcer rate was 0.05 per 1,000 p-y (males 0.07, females 0.02). Gastric ulcer rates were two times higher in 1980 than in 1977. Peptic ulcer age-specific incidence rates increased with age. Incidence rates were much lower than those reported in previous studies, but the gastric to duodenal ulcer ratio and the age and sex relation to ulcer incidence were similar to those previously reported.

Hospitalization and Mortality Rates for Peptic Ulcers: A Comparison of a Large Health Maintenance Organization and United States Data

Hospital discharge and mortality rates for peptic ulcer disease from 1970-1980 for a large Health Maintenance Organization, the Kaiser-Permanente Medical Care Program of Southern California, are compared with the corresponding rates for the United States. The Kaiser-Permanente Medical Care Program hospitalization and mortality age-adjusted rates for ulcers are well below the national rates. In comparison with the 25%-31% decline in the national ulcer hospitalization rate, the Kaiser-Permanente Medical Care Program rate has been relatively stable. Most of the decline in national ulcer hospitalizations is due to a decrease in hospitalizations for uncomplicated cases. The Kaiser-Permanente Medical Care Program uncomplicated hospitalization rates are less than 25% of the national rate after age-adjustment and have been relatively stable over time. The age-adjusted Kaiser-Permanente Medical Care Program rates for ulcers with hemorrhages and perforations are 77% of the national data. These data suggest that part of the decline in national hospitalization rates for peptic ulcer disease may be due to changes in medical management and hospitalization criteria. In addition, this study supports the results of other studies which show that hospitalization rates are lower in Health Maintenance Organizations than in non-Health Maintenance Organizations with no apparent adverse impact on outcome.

Dietary and Other Risk Factors of Ulcerative Colitis: A Case-Control Study in Japan

A multisite, hospital-based, case-control study examined the risk of ulcerative colitis in relation to dietary factors, smoking and drinking habits, past history of diseases, and childhood factors. Information was obtained from self-administered patient questionnaires. Study subjects included 101 ulcerative colitis patients who were 10-39 years old at the time of disease onset, which was within the previous 3 years, and 143 control subjects. Combined consumption of Western foods (bread for breakfast, butter, margarine, cheese, meats, and ham and sausage) was significantly related to an increased risk of ulcerative colitis (trend, p = 0.04). Margarine (as an individual Western food item) was positively associated with ulcerative colitis (trend, p = 0.005). There was also a tendency toward positive association of bread for breakfast with ulcerative colitis (trend, p = 0.07). The risk did not measurably vary with the consumption of typical Japanese foods, vegetables and fruits, confectioneries, or soft drinks. As compared with lifelong nonsmokers, current smokers tended to have a decreased risk of ulcerative colitis and former smokers had an increased risk. There was no association between breastfeeding in infancy and the risk of ulcerative colitis.

Helicobacter pylori infection and atrophic gastritis: a nested case-control study in a rural town in Japan.

A seroepidemiologic, nested case-control studywas conducted to evaluate the risk for atrophicgastritis associated with Helicobacter pylori infection.Atrophic gastritis was diagnosed on the basis of serum pepsinogen levels: pepsinogen I level≤70 ng/ml and pepsinogen I/pepsinogen II ratio≤3.0. Cases were 23 men and 39 women who were notdiagnosed with atrophic gastritis in 1987, but who were diagnosed with the condition in 1992. Controlswere the 120 men and 282 women who did not meet theserologic criteria for atrophic gastritis in either timeperiod. Neither cases nor controls had a history of upper gastrointestinal operations.Helicobacter pylori infection at the initial survey wasassociated with a significantly increased risk ofatrophic gastritis incidence for both sexes combined(odds ratio = 3.72; 95% confidence interval,1.78-7.79; P = 0.0005). Cigarette smoking andconsumption of alcohol and green-yellow vegetables werenot associated with incidence of atrophicgastritis.

Sex and smoking differences in duodenal ulcer mortality.

Data from the US Census Bureau and the National Center for Health Statistics suggest that differences in male and female smoking habits between 1920 and 1980 may have contributed to changes in duodenal ulcer mortality sex ratios. An attributable risk analysis suggests that between 43 per cent and 63 per cent of duodenal ulcer mortality for males results from smoking; the comparable figures for females being between 25 per cent and 50 per cent.

Epidemiological study of peptic ulcer disease among Japanese and Koreans in Japan

Peptic ulcer among Japanese and Koreans in Japan has rarely been studied. In this 10-year study of hospital-based endoscopy, we focused on the epidemiology of peptic ulcer among these ethnic groups in Japan. Between 1980 and 1990, 81.2% of all patients examined via endoscopy at Saikyo Hospital in Kyoto completed a life-style questionnaire: 1,264 Japanese (70.5%), 503 Koreans (28.1%), and 25 persons of unknown ethnicity (1.4%). Characteristics of ulcer disease were almost identical for Koreans and Japanese. Like other world-wide patterns, the male to female ratio was 2.3:1. Unlike results from Western countries, however, the overall gastric ulcer rate was 1.5 times higher than for duodenal ulcer. This higher rate was due to the relatively high rate of gastric ulcer in the older age groups; among persons less than 40 years of age, duodenal ulcer was diagnosed more often than gastric ulcer. The mean age at diagnosis of duodenal ulcer (40.7 years) was significantly lower (p less than 0.005) than that for gastric ulcer (53.7 years). Multivariate-adjusted odds ratios were calculated using a multiple logistic regression model. Cigarette smoking significantly increased the risk for both gastric ulcer (odds ratio = 3.10, 95% confidence interval [CI] 2.1-4.6) and duodenal ulcer (odds ratio = 1.9, 95% CI 1.2-2.9). Age greater than or equal to 40 years (odds ratio = 2.3, 95% CI 1.6-3.3) and consumption of salty foods (odds ratio = 1.5, 95% CI 1.0-2.1) also significantly increased the risk for gastric ulcer.(ABSTRACT TRUNCATED AT 250 WORDS)

Peptic ulcer disease mortality : comparison of Native Japanese, Japanese Americans and Caucasian Americans

Peptic ulcer disease mortality patterns of California Japanese are compared with those of their home and host countries for even years from 1960 to 1988, as well as 1989. Data presented are consistent with the hypothesis that Helicobacter pylori is a necessary but not sufficient causal factor in peptide ulcer disease, and that other co-factors including cigarette smoking and salt intake may be important. Deaths due to peptic ulcer numbered 106 among California Japanese, 12,793 for California Caucasians, 107,461 in Japan, and 117,737 for United States Caucasians during the study period. Data for California Japanese were analyzed separately for California Japanese migrants (i.e., those born in Japan) and U.S.-born California Japanese. California Japanese exhibit site-specific peptic ulcer mortality patterns more similar to those of Japan than of the United States. California Japanese migrants (gastric ulcer:duodenal ulcer = 3.2:1), like Japanese in Japan (gastric ulcer:duodenal ulcer = 6.8:1), die more often from gastric than duodenal ulcer, while California and U.S. Caucasians die as often from duodenal ulcer as gastric ulcer (gastric ulcer:duodenal ulcer = 1:1). California Japanese born in the United States exhibit a ratio between those of California Japanese migrants and California Caucasians (gastric ulcer:duodenal ulcer = 2.3:1). U.S.-born California Japanese have the lowest age-adjusted mortality rates for duodenal ulcer and the second-lowest gastric ulcer rates of all populations examined, even though their gastric to duodenal ratio is similar to that for Japan (which has the highest overall ulcer mortality rate).

A prospective study of dyspepsia in primary care.

Dyspepsia is a common complaint, but its course and associated resource utilization have not been well described. In this study, 288 adult, primary care patients with dyspepsia treated at ambulatory clinics were followed prospectively for one year. Medical chart, utilization, and baseline and one-year follow-up survey data were collected. These patients had 13.3 medical visits (sex- and age-standardized) during the follow-up period, 55% above standardized mean visits for a comparison group of nondyspepsia patients. Standardized mean charges of